Regulating Fish Harvest

Regulating Fish Harvest

Improper harvest of fish ruins future fishing in more potentially good Kansas ponds than any other cause. Pond owners and other anglers are anxious to fish a newly stocked pond and they frequently overharvest the bass population in the first season of fishing. This allows bluegills to overpopulate the pond.

A pond owner can reduce the likelihood of bass overharvest from occurring by not letting anyone fish the pond. This practice is not encouraged, however, because underfishing as well can also lead to problems. Pond owners are urged to let others fish their ponds as long as the pond owner’s rules are followed.

One way to prevent bass overharvest is to release all bass less than 15 inches long for a period of 4 years from stocking, even though bass may be large enough to catch after 1 or 2 years. This means that few bass can be harvested for 4 years from the time of stocking unless adult fish were introduced. If 8-inch bass were stocked, the 15-inch minimum length limit would be needed for only 3 years (2 years if 12-inch bass were stocked).

After 4 years from stocking (2 to 3 years if adult bass were stocked) a management decision must be made. The choice made will depend upon what numbers, sizes, and kinds of fish are desired. Are good sized fish of several species preferred, or is catching large individuals of fewer species more important? Often, quantity has to be sacrificed to achieve greater size.

Five management options are presented here: (1) The “All Purpose Option”; (2) The “Panfish ption”; (3) The “Big Bass Option”; (4) The “Harvest Quota Option”; and (5) The “Catfish Only Option.” The first four options differ from one another in the ways angler harvest of bass is used to manipulate fish populations.

Bass will probably have spawned three times during the 4-year period after fingerlings were stocked or three times in 3 years if 8-inch bass were stocked. If 12-inch bass were stocked, new year classes would have been produced in both years after the original stock were introduced. Young bass produced can come to exist in surplus numbers. If unharvested, poor growth rates occur due to excessive competition. The result will be a bass population comprised primarily of individuals less than 15 inches long.

The guidelines for each of the management options include stocking recommendations for additional fish species. Expected results from a pond not managed according to one of the options are also discussed.

The “All - Purpose Option”

This option affords the opportunity to catch fish of a variety of sizes. To catch bass over 15 inches long with any consistency, numbers of 8- to 12-inch bass must be reduced. In a pond of average fertility, about 30 8- to 12-inch bass should be harvested per acre per year after the fourth year from stocking (second and third year if adult bass were stocked). For high-fertility ponds, as many as 50 small bass might be removed per acre per year. The removal of these small bass reduces competition and makes it possible for some fish to attain lengths over 15 inches.

To ensure that at least 10% of the catchable-size bass survive to lengths of 15 inches and longer, all 12 - to 15 - inch bass that are caught should be released. A good supply of 12 - to 15-inch bass will also reduce densities of intermediate-size bluegills so that some individuals grow to sizes of interest to anglers. This management option will produce bluegills of several sizes, with some reaching 8 inches.

Bluegills and catfish can be harvested as desired. Catfish that are harvested must be replaced with 8-inch or longer individuals to maintain a sizeable catfish fishery. Without periodic supplemental stocking, few catfish will be caught because few young catfish will survive bass predation.

Northern pike can be stocked in large lakes as an additional sport fish and predator as long as the pond owner realizes the fish’s limitations described previously. Rapid northern pike growth rates in Kansas present a threat to survival of original stock bass if pike are stocked too soon. Fingerling pike (6-10 inches) can be stocked at a density of 10 per acre 2 or more years after bass have been introduced. If pike are stocked sooner than this, they may prey on original stock bass or their initial reproduction, preventing a good bass population from developing. Walleye should not be stocked in an impoundment managed according to the “All- Purpose Option” because bluegills do not provide sufficient prey for walleye.

The “Panfish Option”

If catching big panfish is more important than harvesting bass and catching big bass, the pond owner and anglers should continue to release all bass less than 15 inches long past the initial 2-, 3-, or 4-year period after stocking. Bass over 15 inches long can be harvested, but few fish will grow to such a size if the 15- inch length limit is maintained. High densities of 8- to 15- inch bass are more effective in controlling bluegills and other panfish than moderate numbers of bass of several sizes. By purposefully overpopulating bass, the “Panfish Option” will produce more 8- inch and longer bluegills. It is important to note that the “Panfish Option” should be followed only if the pond’s water has an underwater visibility greater than 18 inches. Bluegill and other panfish will overpopulate if bass cannot see well enough to feed on them.

A variation of this management option might include crappie and/or bullheads in the stocking combination along with largemouth bass, bluegills, channel catfish, and fathead minnows.

Crappie and bullheads are not usually recommended for ponds because both fish have a tendency to overpopulate if bass numbers are low or if the pond is muddy and bass cannot see to feed. Problems with crappie and bullheads as well as green sunfish and carp can usually be avoided if a good bass population has developed prior to their gaining access to the pond and if the pond’s water remains clear (an underwater visibility of at least 18 inches).

Twenty adult crappie and/or 20 adult bullheads can be stocked per acre after it is apparent that the pond has sufficient numbers of bass to prey on young crappies and/or bullheads. This situation is demonstrated by the ability of the pond to consistently produce bluegills 8 inches and longer.

Black crappie should be stocked instead of white crappie because black crappie do better than whites in clear water and this option is recommended only when underwater visibility exceeds 18 inches. After adult crappie and ullheads spawn, it will take about 3 years for their offspring to attain lengths of 10 inches and longer.

With crappie and bullheads present, it will be necessary to release nearly all bass that are caught so that crappie and bullhead numbers can be kept under control through bass predation. The quality of bass fishing will be sacrificed to produce good crappie, bullhead, and bluegill fishing because bass must be allowed to overpopulate. Few, if any, bass over 15 inches long would exist in a pond managed in this fashion. If however, fewer than 10% of the bass caught are 12 inches or longer, bass may be too dense, prey too heavily on panfish, and compete with them for food. Approximately 30 bass 8-12 inches long should be removed per acre per year until 10-30% of all bass caught are 12 inches or longer. No harvest restrictions are needed on any species but bass. Northern pike stocked as described in the “All - Purpose Option” might be used to provide additional predation on panfish.

The “Big Bass Option”

To consistently produce bass longer than 18 inches without regard for the size of bluegills, anglers should again release all bass under 15 inches for 4 ears after stocking (2 to 3 years if adult bass were stocked) just as described for the “All- Purpose Option” and the “Panfish Option.” In addition, no bass over 15 inches should be harvested during this period. After that time, densities of 8- to 15- inch bass should be reduced even more than described for the “All- Purpose Option” to allow for rapid growth by survivors. In a pond of average fertility, anglers should harvest 30-50 8-to 12-inch bass per acre per year as well as about 5 12-to 15-inch bass per acre per year. Bass over 15 inches should continue to be released unless a trophy is caught. The odds of a 9-pound bass living another year may not be good, but fish that beat the odds are those that set records.

Twenty adult gizzard shad might be stocked per acre 2 years after bass have been introduced. With adult gizzard shad stocked into the pond, the likelihood of producing a trophy bass is greatly enhanced. Bluegills will serve as the primary prey for small bass, and shad will be eaten by large bass. It is important to realize that stocking gizzard shad involves a certain amount of risk. Without sufficient numbers of bass present, gizzard shad can overpopulate a pond!

This alternative to the basic bass-bluegill-catfish combination is relatively unevaluated, but gizzard shad along with bluegills should produce bigger bass than bluegills alone. With bass eating both kinds of prey, it should be remembered that few bluegills over 6 inches will be present because survival of small bluegills will be higher than would occur without shad. The practicability of this management option may be limited to larger ponds because no more than about 10 bass 3 pounds and larger can be maintained per acre of water.

Since the bluegill population in a pond managed in this fashion will comprise high numbers of small individuals, such a pond might serve to satisfy adult anglers seeking big bass and children trying to catch high numbers of fish with no concern for size. Channel catfish stocking is not required for this management option and harvest of both catfish and bluegills is unrestricted. Periodic supplemental catfish stocking will be required to maintain a population with bass present.

In large impoundment’s managed according to the “Big Bass Option,” fingerling walleye can be stocked 1 year after fingerling bass at a density of 100 per acre. If adult bass are stocked, walleye fingerlings can be stocked simultaneously with bass. Fingerling walleye should be stocked in the middle of the impoundment to avoid shoreline bass predation. It should be realized that by stocking walleye, fewer big bass are likely to be produced because gizzard shad that might have fed only bass will have to support both bass and walleye.

The “Harvest Quota Option”

In the past, ponds have frequently been managed by allowing only a given weight or number of bass to be harvested annually. After the desired bass harvest is achieved, angling must consist entirely of catch and release regardless of the sizes of bass caught. This may occur after one or two trips in small ponds. For the first 4 years after stocking (2-3 years if 8-to 12-inch bass were stocked), little or no bass harvest should occur. After that time, about 20 individuals or 20 pounds of bass can be harvested per acre annually without regard for length.

The potential for bass overharvest is present with this option if the pond owner does not have complete control of fishing access and does not maintain excellent records. Even under good management, this option may not produce bass populations as desirable as those that are managed by the “All- Purpose Option” because the potential for overharvest of large bass and underharvest of small bass exists.

Channel catfish harvest is unrestricted, but catfish removed should be replaced with 8-inch or larger individuals. There is no harvest limit for bluegills using the “Harvest Quota Option.” Historically, pond fish management booklets have suggested that a harvest of from 3 to 10 pounds of bluegills for every pound of bass taken would keep the pond’s fish community in “balance.” While anglers can afford to harvest as many bluegills as desired, such a practice without additional bass harvest restriction will not effectively keep a fish community in good condition. This option is difficult to manage successfully. It is generally best suited for fee fishing recreation areas and children’s fishing ponds.

The “Catfish - Only Option”

The channel catfish is one of the most popular fish in Kansas. In fact, many pond owners want to stock it alone. This is advisable in muddy ponds where sight feeding fish like bass and bluegills would do poorly or in ponds under one-half acre where bass overharvest would likely occur. In large, clear ponds, stocking catfish alone is a waste of space because a pond will produce about the same weight of catfish even if it contains bass and bluegills. The pond owner might just as well take advantage of the angling benefits of all three species.

For a muddy pond or a pond that is smaller than one-half acre, channel catfish-only is the recommended option. The pond should be free of any structure which would provide seclusion for spawning such as sewer tiles, stumps, large rocks, tires, or cream cans. Ponds which contain only catfish are often characterized by excessive numbers of small catfish, when suitable spawning sites exist. If reproduction can be avoided, replacement fish will have to be stocked periodically to maintain the population. Fathead minnows can also be stocked to provide additional food for catfish and a ready source of bait for the pond owner.

This option is the easiest of the five options to manage as long as natural reproduction does not occur. Harvest can begin as soon as fish reach a size considered to be harvestable and no restrictions need exist on the number harvested. As catfish numbers decrease, fishing success will decline, so supplemental stocking will be required to maintain catfish at a density of 100 fish per acre (200 or more per acre with supplemental feeding). Catfish at least 8 inches long should be stocked each fall or spring when the water is cool. The number stocked should equal the number harvested in the previous angling season along with an additional 10% to replace those fish lost to natural mortality.

Catfish production in small or muddy ponds is usually quite low. If the yield of catfish is inadequate, the owner may want to consider a feeding program described later in the " Feeding Fish" section

Consequences of Unrestricted Harvest

Some pond owners do not care enough about fishing to regulate bass harvest. All species of fish are harvested in unrestricted numbers as soon as they are large enough to take a hook. While this may not be considered sound pond management, it is important to illustrate what kinds of fish populations might be expected to develop in a pond fished in such a fashion. The outcome of unrestricted fish harvest will depend upon the number of bass harvested annually. One angler could remove the majority of the original-stock bass from a small pond in a day’s fishing. Such a bass harvest would quickly allow bluegills to overpopulate the pond. Anglers rarely catch the last two bass in a pond, so young bass may continue to be produced. If anglers continue to harvest the majority of bass roduced, bluegills will continue to overpopulate and few large bass will be caught.

Some ponds receive little bass fishing pressure and harvest due to their remote location, because few people fish the pond, or because area anglers do not like to catch small bass. Such ponds eventually develop high numbers of small bass and large bluegills as described in the Panfish Option.” The results from low bass harvest due to low fishing pressure or angler preferences are the same as those that occur with a 15-inch minimum length limit and high fishing pressure. Ponds that normally receive minimal bass harvest can withstand the harvest of an occasional 12-inch bass and even periodic high bass harvests without change because bass reproduction soon returns the pond to crowded bass and large bluegills. Other than habitat changes, annual harvests of 30 or more 8- to 12- inch bass per acre are the only way to increase numbers of larger bass. If harvest of small bass and 12- to 15- inch bass becomes continually high each year, the fish population will eventually become dominated by small bluegills.